The present invention relates to a confocal probe for an endoscopic diagnosis to obtain a high-magnification tomogram of in vivo tissues in a human cavity.
Conventionally, when in vivo tissues are investigated at a thorough examination of a body, tissues at a targeted portion is collected using a cutting forceps or the like, and the collected tissues are investigated extracorporeally. Therefore, it takes relatively long time to obtain a diagnosis result, and an appropriate treatment of a patient cannot be taken immediately.
Recently, in order to accelerate the diagnosis procedure, a confocal probe devices have been widely used. The confocal probe enables an operator to perform a non-invasive observation of a tomogram of in vivo tissues. The confocal probe device typically includes a micro-machined fine probe which is employed in confocal microscopes. The confocal probe is typically provided with a scanning mirror provided inside the probe to scan a laser beam on the target (i.e., human tissues) to capture a two-dimensional or three-dimensional image of the target.
Examples of such a confocal probe are disclosed in Japanese Patent Publications No. 3032720 and No. 3052150. The confocal probe device is generally formed such that optical elements are accommodated in a chamber. Specifically, a scanning mirror is mounted on a base plate made of silicon, and the base plate is secured on an inner wall of the chamber using securing members. Such a structure complicates assembling processes and increases the number of assembling processes.
Further, a positional relationship of the scanning mirror with respect to the other optical elements should be kept very precisely. However, to mount the scanning mirror (i.e., the base plate) at an exact position inside the chamber is very difficult. Further, the securing members should be provided at positions farther from the optical axis with respect to the scanning mirror due to their structural limitations. Accordingly, the entire size of the probe device may be upsized, or at least the diameter of the probe device may become relatively large.